Guest Author - Anu Dubey Dharmani
To know how to increase the life span of flowers, it is better to understand why flowers wilt in the first place. Wilting in flowers is triggered after a successful pollination. Once fertilization occurs, chemicals like ethylene are produced which reduce the water uptake of the flowers. This leads to reduction in food supplies also, eventually causing wilting. So, to enhance the life of flowers this wilt promoting chemical has to be somehow inhibited. There are other factors also which induce floral death. These are the climatic factors, temperature and light.
I will be tackling wilting in two types of orchid flowers: The potted flowers or those growing in the garden and the cut flowers. Both these flowers can be treated to increasing their life span. Various methods as well as chemicals are used in researches and commercially to grow longer lasting flowers.
In case of garden flowers not much can be done about the climatic factors, temperature and sunlight, apart from providing shade. Following can be tried to delay wilting:
• Remove the pollinia of the flowers, taking care not to harm the style or the stigma part. Injury to either of the two (style and stigma) triggers release of wilt causing hormone.
• To counter act the effect of ethylene, foliar spray of cytokinins (like coconut water) has shown positive results2. Cytokinins are commercially available.
• STS (Silver thiosulphate) and 1-MCP (1-Methylcyclopropene) are two chemicals, used by researchers to effectively prevent bud and flower abscission. Foliar application of Silver Nitrate has also been reported to prevent early wilting of flowers and blocking the effect of ethylene (wilt causing chemical).
In case of cut flowers, temperature, lighting as well as the chemical control all can be controlled.
• Higher the temperature, quicker is the wilting of flowers. Flowers look fresher in earlier mornings than in the evenings, because the temperatures rise as the day progresses. For garden flowers not much can be done but cut flowers can be kept in ice/cold water during hot part of the day. You can also add an ice cube or two into the vase.
• Darkness in aids lengthening the life of flowers. Keep your cut flowers away from bright sunlit areas like the windows, where not only the light is brighter but even the temperature is higher.
• Commercial chemicals are also available, which come by the name of flower feeds. Inquire at the nursery or the florist about it. Homemade solutions can also be used. To make homemade flower feeds, take into consideration the basic needs of the flower; water and basic food requirements. A mixture of sugar, salt and lime is the simplest option. I have also come across various tips and suggestions of putting a copper penny in the vase, or adding a little amount bleach to the water (this may be helpful in preventing microbial growth in the water solution), or adding soda water, or adding baking soda etc.
Points to note:
• Cut the flowers early in the mornings, when temperatures are low.
• The cut end of the cut-flower stems dry off and this prevents water uptake when flowers are put in the vase full of water. So, cut a little bit of stem under water with a sharp blade. Under water cutting is advised to prevent air bubbles from inside the water pipe of the stems, which too can stop the water uptake.
• Regularly clean the water of the vase. Microbial growth, evident as cloudy water, can lead to rotting of the stem.